What did Christ do for us so that believing opens heaven's windows even though it happened 2,000 years ago?
Christ paid the sin debt, suffered our punishment, and opened the windows of heaven, so that those who simply believe it receive salvation—even though it happened 2,000 years ago. Salvation is not earned by man's work but is the power of God, the preaching of the cross being foolishness to the perishing but power to the saved.
Les explains that Christ has paid the sin debt, suffered our punishment, and opened the windows of heaven if we will just believe it, even though it happened 2,000 years ago. He then connects this to the preaching of the cross, which is foolishness to those who perish but is the power of God to those who are saved. Les emphasizes that salvation must be an exercise of the sovereign power of Almighty God. That is why man cannot work for his salvation: all man has is physical strength, but only God can bring about the salvation of the spiritual. He also notes that the Jews require a sign and the Greeks seek after wisdom, but Paul says we are not to bother with either. Instead, we preach Christ crucified—unto the Jews a stumbling block and unto the Greeks foolishness, but unto those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God.